As I have described earlier, the summer of 2012 here in Tromsø was not much
of a summer, and the early autumn has continued in the same vein: cool, wet and
often windy weather. The landscape is nevertheless very beautiful these days,
with every birch tree (and we have thousands of them) subtly differently decked
out in autumn colours.There are, however, few birds around ; on a short trip
the other day I saw all of three shore birds: a Reeve, a Spotted Redshank and
to my surprise a Black-tailed Godwit, not a common bird here. It is also a
newcomer, and that has given me the idea that it might be of some interest to
write about the changes in the birdlife of our area, that I have watched in
these thirty years. This is not research, mind you, just my personal
impressions plus what I learned as a museums curator. I hope it may be of some
interest to you, even though it is far away from home.
THE CHANGING BIRDLIFE ON TROMSØYA 1
The town where I have lived the last 40 years, Tromsø in N. Norway (69*50'N),
is situated on the island of Tromsøya, nowadays connected with both a bridge
and a tunnel to the mainland, and with another long bridge to the outlying
large island of Kvaløya, situated between us and the open Norwegian Sea (It is
about 50km by road to the coast). The sounds surrounding the somewhat teardrop
shaped island, with its highest point maybe 200m a s.l., constitute the sill of
the 100km long Balsfjord. On the mainland and on Kvaløya there are higher
hills, with the highest around 1300m, and some of them quite steep. A climber
was killed there yesterday, already the third this year.
When our family moved to Tromsø, in 1973, the town had some 40 000 inhabitants,
but now that has grown to 70 000, and Tromsø is still expanding. There is
little industry here, but fisheries are important, and we have a lot of
facilities following from the fact that Tromsø is the largest town in N.
Scandinavia. We also have a university, the northernmost in the world, if one
excludes the university satellite on Spitsbergen at 78*, where my elder
daughter lives and works. Tromsø Museum where I worked until a few years ago,
is now part of the university, but it is much older, and was founded in 1870!
About half of the island is taken up by the town, but there is still a large
green area 'on top' (jealously kept unscathed, and very actively used by
skiers and walkers), with a largish shallow lake, Prestvannet (the path around
is exactly one mile).
A lot of the irregular changes in our birdlife are a consequence of our
situation in far northern Norway. The large majority of our land birds is
compelled to flee the area in the winter half year (We often have 5-6 months of
snow on the ground, while we also have no sun for two months in midwinter). And
another consequence of our far northern locality is that the ecosystems here
are considerably less diverse than further south, and that makes them also less
stable, so that large oscillations in numbers from year to year are quite
normal. To give some examples: 2011 was a 'lemming-year' many places here
north, with large numbers of rodents: lemmings, voles and mice, and
consequently also large numbers of lemming-predators, such as owls,
Rough-legged Buzzards and Long-tailed Skuas. Last autumn the rodent populations
crashed, and this year the lemming predators were in much smaller numbers and
had to find alternate prey, such as young ptarmigan and shorebirds. This has,
together with our cold and wet summer, resulted in a very bad nesting season
for many bird species.
Other causes of large fluctuations are the large differences from year to year
in the crops of birch seed, pine seeds and Rowan berries. This has great
consequences for the numbers and breeding success of the birds that are
dependent of these food sources, such as i.a. redpolls, crossbills, Pine
Grosbeaks, Bohemian Waxwings and Great Spotted Woodpeckers. In some rich years
they occur here in large numbers, and not rarely some may even stay to nest on
the island the year after; we have had that with crossbills, waxwings and also
Coal Tits, normally a bird on the inland pine forests.
Other changes are a direct consequence of the growth of the town. When I first
came here---we lived two years in new housing in Tomasjordet on the
mainland---, Bluethroats sang from our balcony, and when in 1974 we moved to
our present home on the island, Willow Grouse could be seen now and then in the
garden, a Woodcock was roding outside the house, and on the walk to the museum
there were both Snipe and Sedge Warblers. All this has changed: where I walk to
the museum, there is now a music conservatory, a TV studio, and a home for the
elderly and sick, and virtually all the birds have disappeared; the only
diehards are the Oystercatchers, that now nest oon the flat roofs. I have not
heard the local Woodcocks since more than five years ago (and don't think that
is caused by my problems with hearing these days), and there are no longer
Willow Grouse on our side of the island. All these birds still nest, however,
elsewhere on the island, albeit in greatly reduced numbers. I have earlier
written about the nature areas near the airport here, which have suffered a lot
from both expansion of the airport itself (and regular bird shooting in the
name of air safety), and road improvements. I there wrote that we had lost our
only nesting Temminck's Stints as a consequence; fortunately that was too
pessimistic; one or two pairs still hold out.
A partial success story is that of our local lake, Prestvannet, beloved by the
townspeople for Sunday strolls or jogging, and for 'feeding the ducks' (here
Mallards and just as tame Tufted Ducks). In practice you see the people
struggling mightily to ensure that the local Common Gulls (of which there is a
largish colony here) and the many feral pigeons don't steal the lion's share of
the offered food---umbrellas and walking sticks are avidly used, but to little
avail. Besides the gulls there is also a colony of Arctic Terns here,
fortunately a bit away from the footpaths (nesting terns can be very
aggressive). But the success part of the story are the Red-throated Loons. In
the eighties one pair of loons arrived and nested on the small mud islands in
the lake. This was a success, and now we have at least six pairs displaying,
quarreling and nesting, and they have become quite indifferent to the many
people walking around the lake. Not many places can one watch these loons so
close and undisturbed, I would think. Two years ago I had hopes of a new
attraction, when a pair a Little Gulls prospected the area for two weeks in
spring; sadly they did not stay. This year an otter has established him-(or
her-)self in the lake; it probably mainly feeds on the Crucian Carps that were
introduced 150 years ago (again the northermost in the world, as so many things
here), but I fear the ducklings are in much danger too.
In the second half of this story I shall try to tell a little about the gradual
changes, that May possibly have a connection to global warming.
Wim Vader,
Tromsø Museum
9037 Tromsø,
Norway
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